Compound engine



(No Model.) 3 Sheets-Sheet 1.

A. J. PITKIN. COMPOUND ENGINE.

No. 450,374. Patented Apr. 14,1891.

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(No Model.)

A. J. PIT'KIN. COMPOUND ENGINE.

Patented Apr. 14,1891.

NITE TATES PATENT FFICE.

ALBERT J. PITKIN, OF SGHENECTADY, NEW YORK.

COMPOUND ENGINE.

SPECIFICATION forming part of Letters Patent No. 450,374, dated April14, 1891. Application filed January '7, 1891- Serial No. 376,986. (Nomodel.)

To all whom, it may concern.-

Be it known that I, ALBERT J. IITKIN, a citizen of the United States,residing in the city and county of Schenectady, and State of New York,have invented certain new and useful Improvements in Compound Engines,ofwhich the following is a specification.

My invention relates to compound engines of that class in which live orhigh-pressure steam simultaneously may be admitted to both cylinders orpassed successively through one cylinder to the other. This endheretofore has been attained by means of a branched live-steam pipe andan intercepting-valve interposed between the cylinders and automaticallyactuated in one direction by the live steam to close it and in the otherby the pressure of the steam in the low-pressure cylinder tore-establish this connection. United States Letters Patent No. 417,083,granted to me Docember 10, 1880, illustrate such an organization.

The objects of my present invention are, among other things,automatically to open and close the intercepting-valve by the directaction of live steam; to admit live steam to the low-pressure cylinderthrough a valve actuated by the intercepting-valve instead of opening itby the direct-pressure of the steam, and, finally, to open theintercepting-valve by steam-pressure from the receiver when the engineis running without pressure on the cylinders. These ends I attain bycertain novel combinations and organizations of instrumentalitieshereinafter claimed.

My improvements are applicable to either stationary, portable, orlocomotiveengines.

The accompanying drawings illustrate so much of an engine of the lattertype as is necessary to illustratethe subject-matter claimed. Unlessotherwise indicated, the parts are of usual well-known construction.

Figure 1 represents a front elevation, partly in vertical transversesection, showing the cylinders, their saddles, the smoke-box, thereceiver, and intercepting-valve and steam-passages Fig. 2, a horizontaltransverse section through the interceptingvalve and other valvesrelating thereto on the line 2 2 of Figs. 1 and 4, showing the relationof the parts when the intercepting-valve is open; Fig. 3, a

similar view of some of the same parts in the position they assume whenthe interceptingvalve 1s closed; Fig. 4, a vertical longitudinal sectionthrough the intercepting-valve on the line 4 4 of Fig. 2 with the valveopen. This figure is also a section on the line 3 3 of Fig. 1. Fig. 5 isa vertical transverse section through the regulating and interceptingvalve actuating devices on the line 5 5 of Figs. 2 and 4; Fig. 6, asimilar section on the line 6 6 of the same figures; Fig. 7, a verticallongitudinal section through the regulating devices on the line 7 7 ofFigs. 1, 5, and 6; and Fig. 8, a vertical transverse section through theintercepting-valve on the line 8 8 of Fig. 4.

The feathered arrows indicate the direction in which the steam passesthrough the apparatus, While the short unfeathered darts in Fig. 2 showthe movements of the regulatingvalve and the actuating-piston of theintercepting-valve.

Fig. 1 shows a smoke-box A, mounted on saddles B C, respectivelyconnected with a high-pressure cylinder D and low-pressure Theintercepting-Valve and its appurtenant apparatus are shown as mounted onthe saddle Q of the low-pressure cylinder, while the live-steamconnections and high-pressure exhaust devices are mounted on the othersaddle B. The low-pressure exhaust-pipe E lies centrally between them.The interceptingvalve G somewhat resembles that shown in my patent abovementioned, but differs therefrom in several details of construction,organization, and operation. It consists, essentially, of two pistons GG mounted at suitable distances apart and in fixed relation to eachother on a stem 9 and provided with longitudinal perforations g for thepassage of live steam through these valves or pistons.

TOC

side of the intercepting-valve when closed,

Consequently the live steam, which exerts the greater pressure,compensates any looseness in the fitting of the valve by tending topress itupward against its seat when closed, thus preventing the livesteam leaking into the receiver.

A piston-rod Il, connected with the intercepting-valve, passes throughsuitable stuffing-boxes h h in the heads of the valve-chest and of aseparate cylinder I, provided with a piston H, which actuates theinterceptingval've. This actuating-cylinder I is provided withinlet-portst' z" and an exhaust-port The entrance of steam to thiscylinder-is controlled by a slide-valve 7v on a stem 70, carrying twopistons K K, sliding in a chamber K Steam is admitted to this chamberthrough ports 9', j, and jithe first two admitting steam between thepistons, while the other admits it to act upon the outer end of thelarger piston K, this piston being made larger than the other in orderto insure its movement in the proper direction at the proper time. Livesteam from the boiler passes through a pipe L directly to the highpressure cylinder. A branch pipe L from this pipe connects with a port Zof an auxiliary regulating-chamber M, provided with a piston-valve m,which I call a regulating-valve, traversing across the inlets jj of theregulating-chamber K to open or close them 'at the proper time. A pipe Mconnects the receiver F and its induction-pipe E with this auxiliaryvalvechamber M and with the port 7' Fig. 7, of the chamber K which isprovided at its opposite end with an outletj for the escape of steam orwater which may leak into that end of the chamber. The outlet 1' of thischamber is contracted, as shown in Fig. 5, or provided with means forregulating the escape of the steam therefrom, so as to prevent theslamming of the piston H and of the intercept ing-valves actuatedthereby.

A valve-chamber N contains a puppet-valve N, having two seats n n and astem N ,projecting outside the valve-chamber. A port 41 admits steam tothis valve-chamber from the live-steam branch pipe L, and a passage npermits its escape into the intercepting-valve cylinder 0, and thencethrough the porte to the low-pressure cylinder E below theintercepting-valve, as above mentioned.

An elbow-lever O, rocking on a fulcrum or pivot 0, has its longer armforked, so as to embrace pins 0 on the piston-rod H of theintercepting-valve The other arm 0 of this lever constitutes atappet orwiper, which acts at the proper time on the stem of the puppetvalve N toopen it. This valve is so constructed that its outer member is ofgreater area than its inner. The preponderancy of pressure on the outerend of the valve tends to keep it closed when released from the wiper 0The relation of the wiper and valve-stem may be controlled either byadjusting the collar on its piston-rod or adjusting the wiper.

The operation of the apparatus is as follows: The normal relation of theparts when operating asacompound engine is that shown in Figs. 2 and 4,in which the interceptingvalve is opened and the admission of steam tothe low-pressure cylinder, except through the high-pressure cylinder,receiver, and induction-port E, is cut off. The apparatus is providedwith suitable cutoff or throttle valves. (Not shown in the drawings.) Towork both cylinders with high-pressure steam, a throttle-valve isopened, which permits live or high-pressure steam to pass through thebranch pipe L and port Z to the auxiliary or regulating valve chamber M,the valve m of which it forces to the right, (see Fig. 7,) so as to openthe port j and permit steam to pass into the valve-chamber K between itspistons K K. The right-hand one K of these pistons being of greater areathan the other, the steam-pressure forces them to the right from theposition shown in Fig. '2 to that shown in Fig. 3. This movement causesthe slide-valve 76 to uncover the ports i of the cylinder 1, which inturn "forces the piston H to the right, closing the ports 0 o of theintercepting-valve, as shown in Fig. 2. The relation of theparts is suchthat as the intercepting-valve closes the wiper 0 strikes the stem N ofthe puppet-valve Nand opens it, thus permitting high-pressure steam topass from the pipe L, through the passages 72 of, into theintereept-ingvalve cylinder, and through the port ethe'rein to thelow-pressure cylinder E below the intercepting-valve, thus operating itwith the full pressure of the live steam. The intercepting-valve, asbefore remarked, is already closed, and the tendency of the live steamis to press it upward in its seat, so as to prevent any leakage into thereceiver and consequent back-pressure upon the high-pressure cylinder.The perforations g in the intercepting-valve prevent the steam fromexerting any 'endwise pressure upon it in either direction, and it isconsequently entirely dependent upon the action of the live steam uponits piston 11 in the actuatingcylinder I. The intercepting-valve shouldhave sufficient lap to move slightly beyond its closing-point, inorderthatthe opening of the supply-valve N may not take place until theintercepting-valve is fully closed, the tappet 0 being correspondinglyadjusted. hen it is desired to change from direct to ICC compoundaction, the live steam is cut off from the low-pressure cylinder. Thepressure in the receiver and the induction-pipe E then soon becomessufficient to force steam through the return-pipe M into the auxiliarychamber M and force the regulating pistonvalve m into its sea thusclosing the ports Z andj and simultaneously opening the portj'. Thesteam then passes through this lastnamed port and the port 9' toopposite sides of the larger piston K, the result of which is to forcethe slide-valve k to the left in the position shown in Fig. 2, whichopens the exhaust i and the inlet 2" of the cylinder I and forces thepiston H to the left, thereby opening the intercepting-valve. Thismovement of the piston H detaches the wiper'o from the puppet-valve Nand allows it to close quickly before the intercepting-valve opens. Theparts having thus resumed the position shown in Fig. 2, the engineresumes its compound working. It will also be perceived fromtheforegoingdescriptionthattheinterceptingvalve will automatically beopened whenever the pressure in the receiver is sufficient to overcomethat of the live steam in the auxiliary regulating-valve, andconsequently it is not necessary even to cut off the live steam, unlessit is desired, in order to open the valve quickly at any particularmoment. The intercepting-valve will also be opened even when the steamis cut ofi, as in the case of a locomotive on a downgrade, should therebe sufficient exhaust from the high-pressure cylinder to cause therequisite pressure in the receiver.

The operation maybe concisely stated thus: The opening of the throttleadmits live steam simultaneously to both the high and low pressurecylinders, and by means of this samelive steam acting through amechanism separate and distinct from the intercepting-valve itself thelatter is automatically closed and the en-. gine starts with its fullpower as a simple or non-compound engine. The steam-pressure thus causedin the receiver actsthrough the auxiliary regulating-valve m upon theslidevalve k and opens the intercepting-valve, mechanism connected withwhich releases the valve controlling the admission of live steam to thelow-pressure cylinder, which valve automatically closes itself, thuscausing the parts to resume their compound working. The exhaust-steamdoes not move the intercepting-valve in either direction or exert anyaction upon it whatever.

Havingthus fully described the construction, organization, and operationof my improved compound steam-engine, what I claim therein as new and asof my own invention 1. The combination, substantially ashereinbefore setforth, of a high-pressure cylinder, a low-pressure cylinder, theirconnecting pipe or receiver, an interceptingvalve, its chest, itspiston-rod, a separate cylinder, and a piston therein on theintercepting-valve rod automatically actuated in both directions by thedirect action of the steam in said cylinder to open and close theintercepting-valve.

2. The combination, substantially as hereinbefore set forth, of ahigh-pressure cylinder,a low-pressure cylinder, their connecting pipe orreceiver, an intercepting slide-valve therein, its valve-chest, itspiston-rod, a separate cylinder, a piston therein on theintercepting-valve rod, and a slide-valve regulating the admission ofsteam thereto and automatically driven in both directions by the directaction of the steam therein.

3. The combination, substantially as hereinbefore set forth, of ahigh-pressure cylinder,a low-pressure cylinder, their connecting pipe orreceiver, an intercepting-valve therein, its chest, its piston-rod, aseparate cylinder, a piston therein on the intercepting-valve rod, aslide-valve regulating the admission of steam thereto, and .a steam-pipeconnecting the receiver and actuating-valve chest, so as automaticallyto actuate the valve in both directions to open or close theintercepting- Valve. I

4. The combination, substantially as hereinbefore set forth, of anintercepting-valve,a piston connected therewith, valve mechanismautomatically controlling the movements of the piston, and regulatingmechanism controlling the admission of live or high-pressure steam tothe automatic valve mechanism and piston by the direct action of thesteam upon the regulating mechanism.

5. The combination, substantially as here inbefore set forth, of anactuating-cylinder, its piston, its automatically-actuated valvemechanism, and mechanism automatically regulating the admission of steamto the valve mechanism and cylinder by the direct action of the steamupon the regulating mechanism.

6. The combination, substantially as hereinbefore set forth,of anactuating-cylinder, its piston, its steam-ports, a slide-valve traversing these ports, pistons actuating the slide valve, aregulating-chamber, a valve therein, and steam-ports on opposite sidesthereof admitting steam simultaneously on opposite sides of one of thevalve-pistons to control its movements.

7. The combination, substantially as hereinbefore set forth, of asteam-cylinder, an intercepting-valve, means for actuating itautomatically in either direction by the direct action of live orhigh-pressure steam, a valve controlling the admission of steam to thecylinder, and automatic mechanism actuated from the same source as theinterceptingvalve to actuate the steam-inlet valve.

8. The combination, substantially as hereinbefore set forth, ofahigh-pressure cylinder, a low-pressure cylinder, a receiver, anintercepting-valve, mechanism for actuating it automaticallyin bothdirections by'the direct action of live or high-pressure steam, a valve,regulating the admission of steam thereto,

and steam-inlets on opposite sides of said valve respectively connectedwith the livesteam pipe and With the receiver, whereby the mechanism mayautomatically be actuated either by the direct action of the live steamor by the pressure of that in the receiver.

9. The combination, substantially as hereinbefore set forth, ofahigh-pressure cylinder, a low-pressure cylinder, a receiver, anintercepting-valve, its actuating mechanism, its regulating mechanism, alive-steam pipe admitting steam to the regulator, a pipe connecting thereceiver and regulator, a valve controlling the admission of live steamto the low-pressure cylinder, and automatic mechanism for positivelyopening said valve.

10. The combination, substantially as here inbefore set forth, of anintercepting-valve, mechanism automatically regulating its movements, avalve admitting live steam to theintercepting-Valve, and mechanismadapted to open it automatically, mechanically, and positivelyindependently of the direct action of the steam thereon.

11. The combination, substantially as herei inbefore set forth, of anintercepting-valve, its piston, a valve admitting live steam to theintercepting-valve, and mechanism controlled by the movements of theintercepting-valve positively, automatically, and mechanically to openthe steam-valve.

12. The combination, substantially as hereinbefore set forth, of ahigh-pressure cylinder, a low-pressure cylinder, a receiver connectingthem, a valve-casin g therein, a longitudinallyperforatedintercepting-valve traversing said casing, a piston-rod connecting theintercepting-valve with an actuating-piston in a separate cylinder, avalve admitting live steam to the intercepting-valve, mechanismconnected with the piston for positively opening the valve, and a portin the intercepting-valve casing communicating With the low-pressurecylinder.

in testimony whereof I have hereunto subscribed my name.

ALBERT J. PITKIN.

Witnesses:

ARTHUR M. LANE, R. M. GIFFORD.

